1. Field of the Invention
The present invention relates to a scalar data dimensional scalar data and reconstructing the compressed two-dimensional scalar data.
It is desired to efficiently transmit and reconstruct two-dimensional scalar data, which can be represented as .phi.(x,y) such as luminance data of a picture on a two-dimensional surface or concave-convex data of a relief formed on a wall surface, or to efficiently determine a two-dimensional function .phi.(x,y) of a curved surface of an object such as a car body when the outer shape of the object is to be determined.
2. Description of the related Art
Conventionally, to transmit and reconstruct two-dimensional scalar data, or to determine the two-dimensional function, data of each pixel on the picture surface or each point on the desired body is used. This, however, requires that a tremendus amount of data be processed.
Therefore, an objective has been to enable the reconstruction of two-dimensional scalar data with a small amount of data, smaller than the number of pixels or points on the picture surface.
Reference can be made to U.S. Pat. No. 4,908,698 issued on Mar. 13, 1990, corresponding to Japanese Patent Application Nos. 62-133690 and 63-39284, filed by the same assignee of the present inventors. These applications are directed to providing a color picture synthesis technique in which, in a color picture transmission, a chrominance component of a given picture is separated into a lamellar component and a vortex component for transmission, and a synthesis of the color picture in combination with a luminance component in the above given picture is effected. This technique can be utilized in the present invention.
In the above proposal, the chrominance component is expressed by a vector V, and when the Helmholtz theory is applied to the vector V, it is noted that the vector V can be expressed as: EQU V=grad L+rot(R.multidot.K) (1)
where L(x,y) is a scalar potential such as the luminance, and R.multidot.K is a vector potential having a direction expressed by a unit vector K in the direction of the Z axis.
The lamellar component is the first item, i.e., grad L, in the above expression (1), and the vortex component is the second item, i.e., rot(R.multidot.K), in the above expression (1). By detecting and transmitting an edge line of the chrominance component by detecting only divergence V and rotation V which exceed predetermined threshold values which are the values on the edge line of the chrominance component of the picture, the chrominance component of the color picture for very point can be reconstructed by interpolation.
The present invention was conceived from the above proposal with respect to the chrominance component.